Duplicating



Patented Dec. 14,1926.

UNITED STATES ,P'AT TioFFIcE.

DAVIl'D GESTETNER, OF LONDON, ENGLAND, ASSIGNOR 'I'O D. GES'IETNER, LIMITED; OF

LONDON, ENGLAND.

nurmca'rme.

No Drawing, Application filed Ma -25,1925, Serial No. 32,840, and in 'Great Britain m 11, 1924.

This invention relates to duplicating by the employment-of flexible stencils such, for instance," as" may be formed by stencilizing bv pressure so-called stencil sheets or by photographic means.

By the employment of stencils in duplicating matter in manuscript or type, drawings, photographic prints and thelike, inconvenience is often experienced inconsequence of'anexcessive quantity of ink passin through the openings in the stencil. Not 0 y in such case is theink liable to offset and to run or spread, but further the consumption of ink is unnecessarily great. v

These inconveniences are of course greater or more pronounced where the openings in the stencil are of considerable size.

In the specification of my British Letters Patent No. 148,626 I have described methods of breakin up the stencil at the portions corresponding with what would normally be the solidly inked tion by providing 1n the stencil at such portions ink impermeable elements in the'form of lines, dots or reticulations. The ink resisting elements in a stencil produced by photographic means may, as I have indicated, be formed by exposing a suitable light sensitive pelliole to .the action of light in order tofform thereon a positive or a negative image of a screen which is provided with lines, dots or rcticulations and then again exposing the light sensitive pellicle to the action of hght under conditions adapted to formthereon an image of the matter to be reproduced.

In this wa a stencil is formed which it- ,self is provi ed with elements resisting the passage of ink at those portions of the sten- 40 oil which would normally freely permit ink to passthrough.

The presentinvention is based upon the observation that a similar result can be secured byarranging-behind or' in front of the stencil layer of a stencil of the normal character when in use,a sheet which is pro videdat suitable intervals with elements adapted to resist the passage of ink.

mally these elements will be closely spaced and will constitute 1ine's,dots or' reticulations. A variety of other methods of forming the loo the reti'culations or the like.

portions of the reproduc-' Nor- The invention comprises broadly the imi provement-in duplicating based upon this observation. I

The invention also consists in a sheet adapted to be arranged in association with encil in'the manner above indicated, formed of porous flexible material furnished at intervals with ink resistingelements constituting, for instance, a' series of lines, dots,

The invention further consists in the combination of a stencil or a sheet adapted to be stencilized by pressure or otherwise and a sheet? of porous flexible material furnished at intervals with ink resisting'elements.

A sheet of the character in question may comprise a sheet of porous material such as a felted or woven network of filaments and provided with ink resisting elements of the character above indicated.

- The sheet material used ma be finelawn or other Woven fabric of suificientlyfine texture or it may be a sheet of suitable porous paper such as yoshino paper.

The ink resisting elements maybe formed on the sheet by photographic means; thus, for instance, the sheet may be coated with a layer of alight sensitive material which by exposure to the action of light will be changed in respect to its solubility in certain solvents used as developers in order to form" a plurality of ink impermeablelines, dots or reticulations. For instance, the sheet of porous material maybe coated with'bichromated gelatine and the sheet exposed to the action oflight behind a lined, dotted or re tic'ulated transparency, andafter such exposure the sheet treated in order to remove the portions of the light sensitive composition which have not beenrendered insoluble.

Alternatively, a similar representation of a lined, dotted or -reticulatedsubject may be formed by the action of light on a pellicle of bichromated gelatine or an equivalent light sensitive composition supported upon a suitable backing or support from, which it is transferred to a temporary support for development, the developed image being then transferred to the sheet of porousmaterial.

sheet provided with the ink resisting lines, dots and reticulations may be adopted; for instance, a sheet of asuitable porous material may be subjected to a printing operation by the employment of engraved rollers by which a suitable ink resisting medium may I be applied to theporous material.

A combination stencil sheet in accordance with the invention'including a stencil or a sheet adaptedto be 'sten'cilized by pressure or H otherwise and a sheet of porous material or protector sheet or both in any convenientwith ink resisting furnished at. intervals with' ink resisting the invention a sheet of yoshino paper may be subjected to treatment in the manner spec- V ified abovein order to provide it with lines,

dots-or reticulations of ink resisting material andthe sheet thus obtalned may then be coatedw-ith a composition such, for instance,

as one including a gelatinizingorganic colloid anda temperingpr softening agent enabling the compositlon to be stencilized. by pressure. p

Not only is the arrangement .ofa sheet provided at intervals over the [whole of its surface with ink resisting elements behind a stencil which is not itself provided with ink resisting elements at the portions correspondin with what would normally be the ed portions-of the reproduction solidly i attended with desirable results, but the arrangement in. like manner of such a sheet behind a stencil produced -by photographic means as claimed :in the specification of *in the amount of States Patent No. 1,456,794 or a stencil formed on a sheet as described in the preceding paragraph 7 enables impressions of an improved ap oe to be secured and, further, a reduction In some cases it may be desirableto sub.

ject the yoshinopaper to treatment in known manner in orderto strengthen it or render it more resistant to the destructive agencies recess of.

to which it in the manufacture; for instance, the eat my lightly with a insoluble Alternatively, the paper may be in order to prevmttheoompositlon fo the coating which isadapted to he stencilizedsoakingintoitssuhdmee. In conclusion it is' pointed out customary to arrange a dancil for me in duplicating on a ad which is saturated "with ink or to'secure t e stencil to a flexible car rier of silk gauze or the like and insome cases to arrangebetween the pador gauze carrier a sheet of yoshino or like paper. The action which the pad, gauze or paper has in such conditions on the passage of ink through the stencil is rather inthe direction of equalizing the delivery of the ink therethrough to secure what may be considered a normal degree of inking of the impression receiving surface, Whereas a screen or sheet according to the present invention definitely reduces the quantity of ink transferred to the impression receiving surface and will be arranged between the stencil. and the pad or the stencil carrier to effect this result. J

Having now described my invention what I claim as new and desire to secure by Letters Patent is i 1. The improvement in duplicating b I the employment of flexible stencils, whic comprises providing ink-resisting elements, suitably spaced 'apart,'over anarea co-extensive with the areaof the stencil layer.

2. The improvement in duplicating by the I employment of flexible stenclls, which.-comprises arranging in associationwith the stencil layer of a stencil of the normal character,

when 1n. use, a sheet which is provided at' suitable'intervals with elements adapted ,to resist the passage of ink. L

3. The improvement in duphcating by the aid of flexible stencils, which comprises arranging in association with the stencil la er of a stencil of the normal character, w en in use, a sheet of porous flexible material furnished -at intervals with ink-resisting ele ments constituting a series of lines. 44. For use in duplicating with the aid of stencils, a sheet adapted to be arranged in association with the stencil, formed of porous'flexible material furnished at uniform intervals .over the whole of its surface with ink-resisting lements.-

5. For use in duplicating with the aid of stencils, a sheet adapted to be arranged in association with the steneikformed of porous flexiblirmaterial furnished at uniform intervals the whole of its surface with ink-resistmg elements constituting a series of lines. 7

6; For use in duplicating'with file aid of stencils, the combination ofa sheet adapted to be stencilized by pressure and a sheet ofporous flexible material furnished at intervals with ink-resisting elements.

7. For use in dnplica a sheet prising a sheet of yoshino'paper and. pro: vided with ink-resisting elementsoonstltutg a series of lines uniformly disposed over the whole of its surface. that-it is- 8. A combination stencil sheet including a to'be stencilizedfbyp .and a sheet of porous material furnished at intervals with ink-resisting elements,

the two said sheets being secured together.

9. A combination stencil sheet including a sheet adapted to be stencilized by pressure and a' sheet of porous material furnished at intervals with ink-resistin elments the two said sheets being secure together and secured to a backing sheet.

10. A combination stencil sheet including i a sheet adaptedto be steneili'zed by pressure and a sheet of porous material furnished at I intervals with ink-resisting element's,

secured together end secured to a backing sheet and a protector two said sheets being sheet.

In testimony whereof have signed my name to this specification.

DAVID GESTETNER.

the 

